1. Field of the Invention
The present invention relates to visual simulator devices and particularly to visual simulation devices utilizing helmet mounted projectors. More particularly, the present invention relates to a helmet mounted visual simulation device for projecting computer generated images onto a domed screen utilizing a laser raster scan. In greater particularity, the present invention may be described as a helmet mounted optical scanning assembly for deflecting modulated laser rasters to produce images on a retroreflective screen.
2. Description of the Prior Art
The training of pilots in ground based simulators to perform mission tanks such as air-to-ground weapon delivery, low level high speed navigation, and confined area maneuvering requires wide angle presentation of a simulated real world environment.
Previous techniques have included the use of a large number of display channels in a mosaic arrangement about the observer. The number of display windows or channels required for such an approach is a function of the desired field of view, resolution, and the number of picture elements which can be provided by a window. A field of view requirement of two-thirds of a complete sphere combined with a resolution requirement for picture elements to subtend two arc minutes would require more than thirty display windows, thus requiring an image generator with more than thirty channels.
Alternatively, a helmet mounted display generator in a small CRT coupled directly to the observer's eye may be used. By appropriate means for sensing the observer's head direction, a display "window" which follows the observer's head direction can be generated. The disadvantage of such a system is the limited field of view available to the observer at any one head position.